The astronauts are ready to come back to Earth on Friday. We hear about upgrading the Hubble Space Telescope, what age-old questions it's now prepared to address and whether manned space flight has a future. Also, President Obama announces the first-ever national emissions standards, and Britain's expense account scandal takes a political toll.

FROM THIS EPISODE

The astronauts are ready to come back to Earth on Friday. We hear about upgrading the Hubble Space Telescope, what age-old questions it's now prepared to address and whether manned space flight has a future. Also, President Obama announces the first-ever national emissions standards, and Britain's Speaker of Parliament is forced out for the first time in 300 years.

Banner image: (May 18, 2009) Astronaut John Grunsfeld, STS-125 mission specialist, participates in the mission's fifth and final session of extravehicular activity as work continues to refurbish and upgrade the Hubble Space Telescope. During the seven-hour and two-minute spacewalk, Grunsfeld and astronaut Andrew Feustel (out of frame), mission specialist, installed a battery group replacement, removed and replaced a Fine Guidance Sensor and three thermal blankets protecting Hubble's electronics.

Michael Martin has been a Member of Britain's House of Commons from Glasgow for 30 years and Speaker for nine. Public outrage at Parliament has reached such a pitch that the Martin has been forced to resign — the first time that's happened in 300 years. It's all about expense accounts and reimbursements for lavish excesses, reports of which were leaked to the press. Jonathan Freedland is a columnist at the Guardian newspaper.

Astronaut-astronomer John Grunsfeld calls the Hubble Space Telescope "arguably the most important scientific instrument ever created," important enough for him and others to risk their lives walking in space for five days to make repairs. Now it's almost time to come home. We look at what they did and what the Hubble might find as it looks back farther than ever toward the origin of the universe and the beginning of time. We also consider what's next for the manned space program. Would a return to the Moon and a visit to Mars be cheaper and more effective with robots?

President Obama today announced new standards to improve the fuel efficiency of cars and trucks and reduce greenhouse gases. The President made much of the new consensus among old enemies. Jim Tankersley reports on energy and environmental policy for the Tribune Company.